Study On Simulation Of Heating Process And Energy-saving Process Parameters Of Drying Cylinder

In the process of producing asphalt mixture,asphalt mixing plant consumes a lot of energy and materials.To achieve energy saving and emission reduction in highway construction,the asphalt mixing plant is required good energy saving ability.Cold aggregate drying and heating is one of the most energy-consuming process in the production of the asphalt mixing plant.The study of the process and process parameters of aggregate heating is of great significance for energy saving in the asphalt mixing plant.This paper uses CFD-DEM coupled numerical simulation method to simulate the heating process of the aggregate of the drying zone.According to the motion state and form of heat transfer of the aggregate and the flue gas,the contact model of the aggregate and the drag force model of two-phase and the heat transfer model are determined.Fluent and EDEM software is used to calculate the movement and heat transfer of the aggregate and flue gas.A three-dimesional geometric model of the drying zone of the drying drum of the model4000 asphalt mixing is established and the heating process of the aggregate in the drying zone is simulated.The temperature change of the aggregate discharge is analyzed and the temperature gradient of the flue gas is obtained.The aggregate in the steady state and the time required for the drying drum to reach the stable working state is determined.According to the heat transfer mechanism of the drying zone,a mathematical model of the heat transfer of the aggregate is established and the influence of the process parameters such as the flue gas flow rate,the rotating speed of the drum and the productivity of the drying drum on the heating of the aggregate is analyzed.The orthogonal experiment method is used to design the simulation test.The average temperature of the drying drum and outlet temperature of the flue gas as the test indicators are considered.The matrix analysis method is used to evaluate the test results of different process parameters.The energy-saving process parameters of the drying drum of the 4000 type asphalt mixing plant are determined as follows: the productivity is 240t/h,the flue gas flow rate is 4m/s,and the drum speed is 8.5r/min.